Study On Ultimate Bearing Capacity Of New Epoxy Resin Concrete Assembled Truss Joints

New epoxy resin concrete has the advantages of high strength,good durability,fast strength growth,good toughness,short molding time,easy construction and so on,and is widely used in the field of materials.In this paper,a new type of epoxy resin concrete is proposed as the structural material for truss structural system design.The joint area is formed by connecting chord members,web members and joint plates of the new type of epoxy resin concrete through bolts.In the design of truss structure system,the joint region is the most complicated region in the whole truss structure.In order to ensure the joint region to bear common force and coordinate deformation,the research on the mechanical performance,failure mode and ultimate bearing capacity of the joint affects the stability and safety of the whole truss structure,which has important research significance and practical value.In this paper,a new type of epoxy resin concrete assembled truss joint,which is made up of standard connectors and common bolts,is used as the research object.Through theoretical analysis,numerical simulation and experimental design,the optimal mix ratio of the new type of epoxy resin concrete is explored,the compressive strength,compressive strength and elastic modulus tests are conducted to determine the material properties and constitutive relation of the new type of epoxy resin concrete.Based on the statistical analysis of engineering application,the stress characteristics of truss structures at the stage of emergence are summarized for truss models made of different materials,and the truss structure system conforming to this test is determined.According to the mechanical properties of epoxy resin concrete materials,finite element models of different types of joints are established to simulate the whole stress process under load.By simulating the effects of different thickness of gusset plates,different bolt diameters,different bolt numbers and the distance between bolts and the edge of gusset plates on the mechanical properties of the joints,the stress magnitude and distribution laws on chord members,gusset plates,web members and the ultimate bearing capacity and load-displacement curves of the joints under the optimal schemes are obtained,and reference opinions are provided for the joint tests based on this.Using finite element non-linear numerical analysis software ABAQUS,the optimal scheme is selected for experimental design,chord members,web members and joint plate specimens are made,and the experimental scheme of ultimate bearing capacity of the joint is proposed.This paper provides theoretical support and reference basis for future experimental research and the establishment of new epoxy resin concrete truss structure system.